Ample evidence demonstrates that public health elements such as preventive care reminders, quality measurement, immunization registries, and patient education materials provide public health value, yet dissemination is poor. Electronic health records (EHRs) may provide a solution, but poor EHR adoption and poor incorporation of public health elements into EHRs limit their broad use. The New York City government is carrying out a unique project to improve the health of the city, investing over $27 million to implement a public health enabled EHR (PHEEHR) to providers who treat underserved patients throughout the city. Our project is to study this PHEEHR New York City implementation with the goal of discovering strategies that can enhance PHEEHR adoption and impact. Specific aims are 1) to study the implementation process by examining across practice settings the contextual factors that contribute to the adoption and impact of the PHEEHR;2) to study how the complex relationships between public health elements and environmental task elements facilitate or hamper adoption and impact of the PHEEHR and 3) to develop and disseminate generalizable conclusions based on the results of aims 1 and 2. We will use the DeLone and McLean Information System Model to evaluate the causal paths that begin with the PHEEHR system itself, and incorporate user satisfaction, adoption, and impact. Impact in this study is multifaceted measured in part by an increase in the proportion of provider sites that perform preventative services and public health reporting based on Healthy People 2010 and the U.S. Preventive Services Task Force guidelines. The DeLone and McLean model and an extended model with a task-technology fit construct will be empirically tested with quantitative qualitative and relational data collected from 327 practice settings. Multilevel structural equation modeling (ML-SEM) will be used to evaluate both models. To maximize the generalizability of our findings, we will adhere to standardized multidimensional reporting metrics from the RE-AIM framework specifically designed to improve the translatability of research findings. Our goal is to extend what we learn from this unprecedented New York City PHHEHR implementation research study to inform others that are likely to engage in similar PHEEHR implementations in the future.